Well, you would if you had OnStar’s Family Link. In fact, you would know where your wife or husband was too. That’s because it tracks every single car in the family’s garage, letting you see exactly where everyone is on the Family Link website.

Last year, we had more than 4,500 subscribers test the Family Link service and they told us it provides them peace of mind by staying connected to their family when they’re on the road.

The $3.99-per-month service will start rolling out to select subscribers in mid-April, with more subscribers getting invitations in June.

The technology behind it isn’t mind-blowing. Basically, any vehicle outfitted with General Motors’ OnStar system uses GPS to transmit its location. If you’re sitting at home, all you have to do is click on the icon representing a particular car and its location will pop up on a map, minus any information on speed or where it’s headed.

The appeal is obvious. Who wouldn’t want to know that their teens were safely on their way home instead of cruising about the main strip with all sorts of slackers and no-goodniks?

The problem, of course, is that you’re trusting that people won’t abuse this service and also that the service can never be hacked. An OnStar representative told Wired, “We are depending on subscribers to tell other family members that they’ve enabled the service on the vehicle.”

This kind of GPS-enabled technology isn’t new. There was a similar hubbub when several phone carriers let parents turn on child-locator services. Lots of people give away their location willingly when they log in to Highlight or Google Latitude.

That doesn’t mean we shouldn’t give it the same amount of scrutiny we give every other geo-location product. It’s easy to see how Family Link could be abused by, say, a jealous husband or wife tracking his or her spouse’s every movement. Not to mention the dangers inherit with every family member sharing one username and password.

Still, there’s nothing too egregious about this particular service. Pile it on top of several other similar products, however, and you could have yourself one uncomfortably paranoid family.